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<refentry version="5.0-subset Scilab" xml:id="gf_cont_struct" xml:lang="en"
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  <refnamediv>
    <refname>gf_cont_struct</refname>
    <refpurpose>  This object serves for storing parameters and data used in numerical
  continuation of solution branches of models (for more details about
  continuation see the Getfem++ user documentation).
</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <title>Calling Sequence</title>

    <synopsis>S = gf_cont_struct(model md, string dataname_parameter[,string dataname_init, string dataname_final, string dataname_current], scalar sc_fac[, ...])</synopsis>
  </refsynopsisdiv>

  <refsection>
    <title>Description</title>
    <para>General constructor for cont_struct objects.</para>

    <para>  This object serves for storing parameters and data used in numerical
  continuation of solution branches of models (for more details about
  continuation see the Getfem++ user documentation).
</para>
  </refsection>

  <refsection>
    <title>Command list</title>

    <itemizedlist>
    <listitem>
    <para><literal>S = gf_cont_struct(model md, string dataname_parameter[,string dataname_init, string dataname_final, string dataname_current], scalar sc_fac[, ...])</literal></para>

    <para>       The variable <literal>dataname_parameter</literal> should parametrise the model given by
    <literal>md</literal>. If the parametrisation is done via a vector datum, <literal>dataname_init</literal>
    and <literal>dataname_final</literal> should store two given values of this datum
    determining the parametrisation, and <literal>dataname_current</literal> serves for actual
    values of this datum. <literal>sc_fac</literal> is a scale factor involved in the weighted
    norm used in the continuation.
    
    Additional options:
    
    - 'lsolver', string SOLVER_NAME
       name of the solver to be used for the incorporated linear systems
       (the default value is 'auto', which lets getfem choose itself);
       possible values are 'superlu', 'mumps' (if supported), 'cg/ildlt',
       'gmres/ilu' and 'gmres/ilut';
    - 'bifurcations'
       activates tools for detection and treatment of bifurcation points;
    - 'h_init', scalar HIN
       initial step size (the default value is 1e-2);
    - 'h_max', scalar HMAX
       maximum step size (the default value is 1e-1);
    - 'h_min', scalar HMIN
       minimum step size (the default value is 1e-5);
    - 'h_inc', scalar HINC
       factor for enlarging the step size (the default value is 1.3);
    - 'h_dec', scalar HDEC
       factor for diminishing the step size (the default value is 0.5);
    - 'max_iter', int MIT
       maximum number of iterations allowed in the correction (the default
       value is 10);
    - 'thr_iter', int TIT
       threshold number of iterations of the correction for enlarging the
       step size (the default value is 4);
    - 'max_res', scalar RES
       target residual value of a new point on the solution curve (the
       default value is 1e-6);
    - 'max_diff', scalar DIFF
       determines a convergence criterion for two consecutive points (the
       default value is 1e-6);
    - 'min_cos', scalar MCOS
       minimal value of the cosine of the angle between tangents to the
       solution curve at an old point and a new one (the default value is
       0.9);
    - 'max_res_solve', scalar RES_SOLVE
       target residual value for the linear systems to be solved (the
       default value is 1e-8);
    - 'non-smooth'
       determines that some special methods for non-smooth problems can be
       used;
    - 'delta_max', scalar DMAX
       maximum size of division for evaluating the test function on the
       convex combination of two augmented Jacobians that belong to different
       smooth pieces (the default value is 0.005);
    - 'delta_min', scalar DMIN
       minimum size of division for evaluating the test function on the
       convex combination (the default value is 0.00012);
    - 'thr_var', scalar TVAR
       threshold variation for refining the division (the default value is
       0.02);
    - 'nb_dir', int NDIR
       number of linear combinations of vectors in one subspace when
       searching for new tangent predictions during location of new one-sided
       branches (the default value is 40);
    - 'nb_comb', int NCOMB
       maximum number of couples of reference vectors forming the linear
       combinations (the default value is 1);
    - 'noisy' or 'very_noisy'
       determines how detailed information has to be displayed during the
       continuation process (residual values etc.).
    </para>
    </listitem>

    </itemizedlist>
  </refsection>

  <refsection>
    <title>See Also</title>
    <simplelist type="inline">
      <member><link linkend="getfem_types">getfem types</link></member>
    </simplelist>
  </refsection>

  <refsection>
    <title>Authors</title>
    <para>Y. Collette</para>
  </refsection>

</refentry>
